The list of losers in the sub-prime loan crisis is long: borrowers, investors, banks, anyone whose livelihood depends on the availability of credit—and homeowners whose homes are being foreclosed.

But there are winners, and one of them made a killing in a manner that reminds us that in business, as in the rest of life, there is no substitute for morality.

That winner was the powerful investment bank Goldman Sachs, whose former chairmen include the current Secretary of the Treasury, the governor of New Jersey, and the Treasury Secretary under President Clinton. According to the Wall Street Journal, late in 2006, traders in its Structured Products department convinced bank executives that the “sub-prime market was heading for trouble.”

What did Goldman do? It sold off much of its “stockpile” of mortgage-backed securities. In addition, the bank’s traders bet—what is called “selling short”—that the market would go down.

This paid off handsomely: The bank generated “nearly $4 billion of profits during the [fiscal] year ended Nov. 30,” easily erasing mortgage-related losses in the rest of the firm.

The bank’s customers? They did not do so well. Maybe that is because Goldman Sachs kept selling mortgage-backed securities at the same time it was betting that they would lose value.

Goldman’s “success at wringing profits out of the sub-prime fiasco,” the Wall Street Journal says, “raises questions about how the firm balances its responsibilities to its shareholders and to its clients.”

Ben Stein, who was a colleague of mine in my White House days, was more direct, writing that the firm continued “injecting dangerous financial products into the world’s commercial bloodstream” even after it became convinced they were “horrible.”

“It is bad enough,” Stein wrote in the New York Times, “to have been selling this stuff.” “It is far worse,” he added, “when the sellers were, in effect, simultaneously shorting the stuff they were selling.”

In case you were wondering: None of this is illegal. It may “raise questions,” but record profits have a way of answering those questions for many people.

No, there is only one thing keeping firms like Goldman Sachs from selling something while at the same time betting against it. That one thing is moral restraint.

Unfortunately, that is exactly what’s missing in our morally relativistic culture. Without a belief in moral absolutes, the only real basis for investor confidence is regulation and other legal coercion. And the sub-prime crisis will lead to much more regulation.

The problem is that regulations often interfere with the efficient operation of markets. For instance, reforms passed in the wake of the Enron scandal had the unintended effect of driving lucrative public offering business overseas.

So you see, free markets—and capitalism itself—can thrive only when corporations and individuals exercise moral restraint. When those restraints fail, government regulation is sure to follow, which in turn makes free markets less free.

Of course, moral restraint requires a set of morals, beliefs that some things are wrong, regardless of what the law says—or, put more simply, the biblical worldview. Otherwise, who can trust people to do what is right when they can make a killing by doing what is wrong? That’s a lesson that Goldman’s clients and millions of homeowners have learned the hard way.